Convert test_fec to gtest
Convert test_fec to gtest

All tests needs to be gtest tests in order to be executed
with the upcoming isolate/swarm framework.

TEST=trybots passing
BUG=1916
R=andrew@webrtc.org, marpan@google.com

Review URL: https://webrtc-codereview.appspot.com/1647005

Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 22bbbdfa6809a2fb543c6c26d022804df06a4f2c

sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc